In this case report, we present a case of thoraco-omphalopagus conjoined twins who were successfully separated and had long-term survival. We performed ultrasound assessment and found that the twins shared the liver and that the fusion site of their liver had gross communication of blood vessel. Ultrasound cardiogram examination showed that the anomalous vessels that connected their hearts drained from the number 1 infant to the number 2 infant. The ultrasound assessment has significant impact on the successful surgical separation of the thoraco-omphalopagus twins.